Method of regulating the advance of articles in a conveyor system, particularly an automatic packaging system, and the system concerned

Abstract

In a conveyor system including a main conveyor line and a plurality of branch lines, when there is a stoppage in one of the branch lines, the operating speeds of the branch lines which are still active are increased so as to ensure that the entire flow of articles is disposed of. Each branch line which is still active changes to the faster operating speed only after it has been found that articles have actually accumulated on that branch line.

What is claimed is: 
     
       1. A method of advancing articles in a conveyor system having a main conveyor line on which a flow of articles advances,   a plurality of branch lines which can operate at a normal operating speed and at least one faster speed and onto which respective fractions of the flow of articles are transferred, and a user station associated with each branch line,   the method including the steps of detecting stoppage of at least one branch line, detecting a formation of a predetermined accumulation of articles on each of other branch lines which have not experienced stoppage causing the other branch lines to operate at a faster speed in order to ensure that the flow of articles is taken up,   but only when the predetermined accumulation of articles has formed on at least one of the other branch lines.   
     
     
       2. A method according to claim 1, applied to a conveyor system in which each branch line has in cascade: a withdrawal station for withdrawing articles from the main conveyor, and   a conveyor, wherein the method includes the steps of:   causing the withdrawal station of each branch line which is still active to operate at the faster speed when the stoppage of another branch line has been detected, and   keeping the conveyor and the user station at the normal, slower operating speed until the formation of an accumulation on the conveyor is detected.     
     
     
       3. A method of advancing articles in a conveyor system having a main conveyor line on which a flow of articles advances, a plurality of branch lines which can operate at a normal operating speed and at least one faster speed and onto which respective fractions of the flow of article are transferred, and storage means for temporarily storing any articles which have not been transferred onto the branch lines, comprising the steps of detecting stoppage of any branch line and causing the other branch lines which are still active to operate at a faster speed in order to ensure that the flow of articles is taken up, detecting the formation of any accumulation of articles on each of the branch lines which are still active and bringing about the operation at a faster speed only when there is an accumulation, detecting the presence of articles on the storage means, and causing the branches to return to the normal operating speed after an acceleration to the faster speed only after all the articles on the storage means have been disposed of. 
     
     
       4. A system for conveying articles comprising: a main line for conveying a flow of articles,   a plurality of branch lines which can operate at a normal operating speed and at least one faster speed in order to transfer respective fractions of the flow of articles,   a user station associated with each branch line,   means for detecting stoppage of any branch line and causing the other branch lines which are still active to operate at a correspondingly faster speed to ensure that the flow of articles is taken up,   sensor means for detecting the formation of any accumulation of articles on each branch line which is still active, and   control means for bringing about the operation at the faster speed only when there is a predetermined accumulation of articles on the still active branch lines and configured such that operation of the user stations associated with the still active branch lines is precluded prior to the predetermined accumulation of articles.   
     
     
       5. A system according to claim 4, wherein each branch line has in cascade: a withdrawal station for withdrawing articles from the main conveyor, and   a conveyor, and wherein the control means accelerate the operation of the withdrawal station of each branch line which is still active to the faster speed when the stoppage of another branch is detected but keep the conveyor means and the user station at the normal operating speed until the sensor means detect the formation of an accumulation on the conveyor means.     
     
     
       6. A system according to claim 4, wherein the sensor means comprise optical sensors. 
     
     
       7. A system according to claim 4, wherein it includes storage means for temporarily storing any articles which have not been transferred onto the branch lines and further sensor means for detecting onto the branch lines and further sensor means wherein the control means cause the branch lines to return to the normal operating speed after an acceleration to the faster speed only when the further sensor means detect that all the articles on the storage means have been disposed of. 
     
     
       8. A system for conveying articles, comprising a main line for conveying a flow of articles, a plurality of branch lines which operate at a normal operating speed and at least one faster speed in order to transfer respective fractions of the flow of articles, means for detecting the stoppage of any branch line and causing the other branch lines which are still active to operate at a correspondingly faster speed to ensure that the flow of articles is taken up, sensor means for detecting the formation of any accumulation of articles on each branch line which is still active, control means for bringing about the operation at a faster speed only when there is an accumulation, storage means for temporarily storing any articles which have not been transferred onto the branch lines, and additional sensor means for detecting the presence of articles on the storage means, wherein the control means cause the branch lines to return to the normal operating speed after an acceleration to the faster speed only when the additional sensor means detect that all the articles on the storage means have been disposed of.